Antenna Q

The Q of an antenna is a measure of the bandwidth of an antenna relative to the center frequency of the bandwidth. If the antenna operates over a band between f1 and f2 with center frequency fc=(f1+f2)/2, then the Q is given by: Antennas with a high Q are narrowband, antennas with a low Q are wideband. The higher the value of Q, the more sensitive the input impedance is to small changes in frequency.